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Nissan Sentra B18 (2020-2025) Service Manual / Restraints / Srs Air Bag Control System :: Symptom Diagnosis

Nissan Sentra B18 (2020-2025) Service Manual: Srs Air Bag Control System :: Symptom Diagnosis

Srs Air Bag Warning Lamp Does Not Turn Off. Diagnosis Procedure. Diagnosis Procedure

Diagnosis Procedure

  1. CHECK AIR BAG MODULE AND SEAT BELT PRE-TENSIONER

    1. Check the deployment of air bag module.

    Is air bag module deployed?

    YES >>

    Replace the malfunctioning parts.

    NO >>

    GO TO 2.

  2. CHECK AIR BAG FUSE

    1. Check 10A fuse [No. 46, located in fuse block (J/B)].

    Is the inspection result normal?

    YES >>

    GO TO 3.

    NO >>

    Replace the fuse.

  3. CHECK HARNESS CONNECTOR

    1. Check the harness connector.

    Is the inspection result normal?

    YES >>

    GO TO 4.

    NO >>

    Replace harness connectors.

  4. CHECK WIRING HARNESS

    1. Check the wiring harness externals.

    Is the inspection result normal?

    YES >>

    GO TO 5.

    NO >>

    Replace wiring harness.

  5. REPLACE AIR BAG DIAGNOSIS SENSOR UNIT

      1. Replace air bag diagnosis sensor unit. Refer to Removal and Installation.

      2. Check air bag warning lamp operation.

    Is the inspection result normal?

    YES >>

    Inspection End.

    NO >>

    GO TO 6.

  6. REPLACE COMBINATION METER

      1. Replace combination meter. Refer to Removal and Installation (Type A) or Removal and Installation (Type B).

      2. Check air bag warning lamp operation.

    Is the inspection result normal?

    YES>>

    Inspection End.

    NO>>

    GO TO 1.

Srs Air Bag Warning Lamp Does Not Turn on. Diagnosis Procedure. Diagnosis Procedure

Diagnosis Procedure

  1. CHECK COMBINATION METER POWER SUPPLY AND GROUND CIRCUIT

    1. Check combination meter unit power supply and ground circuit. Refer to Diagnosis Procedure (Type A) or Diagnosis Procedure (Type B).

    Is the inspection result normal?

    YES >>

    GO TO 2.

    NO >>

    Repair or replace the malfunctioning parts.

  2. CHECK HARNESS CONNECTOR

    1. Check the harness connector.

    Is the inspection result normal?

    YES >>

    GO TO 3.

    NO >>

    Replace harness connectors.

  3. CHECK WIRING HARNESS

    1. Check the wiring harness externals.

    Is the inspection result normal?

    YES >>

    GO TO 4.

    NO >>

    Replace wiring harness.

  4. CHECK AIR BAG DIAGNOSIS SENSOR UNIT

    1. Disconnect air bag diagnosis sensor unit connector and place ignition switch in the ON position.

    Does air bag warning lamp turn ON?

    YES >>

    Replace air bag diagnosis sensor unit. Refer to Removal and Installation.

    NO >>

    Replace combination meter. Refer to Removal and Installation (Type A) or Removal and Installation (Type B).

Seat Belt Warning System. Seat Belt Warning System Does Not Function. Seat Belt Warning System Does Not Function

Seat Belt Warning System Does Not Function

  1. SEAT BELT WARNING LIGHT

    1. Ignition switch ON.

    Does the front seat belt warning lamp come ON?

    YES >>

    GO TO 2.

    NO >>

    • Check 5A fuse [No. 47, located in the fuse block (J/B)].

    • Check front seat belt buckle switch LH.

    • Check harness between BCM and front seat belt buckle switch LH.

    • Check combination meter. Refer to Fail-Safe (Type A) or Fail-Safe (Type B).

  2. FRONT SEAT BELT BUCKLE LH

    1. Fasten the front seat belt buckle LH.

    Does the front seat belt warning lamp go OFF?

    YES >>

    GO TO 3.

    NO >>

    • Check front seat belt buckle switch LH.

    • Check harness between BCM and front seat belt buckle switch LH.

  3. OCCUPANT CLASSIFICATION SYSTEM

    1. Have a helper sit in the passenger seat.

    Does the front seat belt warning lamp go ON?

    YES >>

    GO TO 4.

    NO >>

    • Check occupant classification system. Refer to System Description.

    • Check harness between occupant classification system control unit and air bag diagnosis sensor unit.

    • Replace air bag diagnosis sensor unit. Refer to Removal and Installation.

  4. FRONT SEAT BELT BUCKLE RH

    1. Fasten the front seat belt buckle RH.

    Does the front seat belt warning lamp go OFF?

    YES >>

    GO TO 5.

    NO >>

    • Check front seat belt buckle switch RH.

    • Check harness between front seat belt buckle switch RH and air bag diagnosis sensor unit.

    • Replace air bag diagnosis sensor unit. Refer to Removal and Installation.

  5. REAR SEAT BELT BUCKLE LH

    1. Start the engine and fasten the rear seat belt buckle LH.

    Does the corresponding rear seat belt indicator appear grey?

    YES >>

    GO TO 6.

    NO >>

    • Check rear seat belt buckle switch LH.

    • Check harness between rear seat belt buckle switch LH and air bag diagnosis sensor unit.

    • Replace air bag diagnosis sensor unit. Refer to Removal and Installation.

  6. REAR SEAT BELT BUCKLE RH & CTR

    1. Fasten the rear seat belt buckle RH & CTR.

    Does the corresponding rear seat belt indicator appear grey?

    YES >>

    System OK.

    NO >>

    • Check rear seat belt buckle switch RH & CTR.

    • Check harness between rear seat belt buckle switch RH & CTR and air bag diagnosis sensor unit.

    • Replace air bag diagnosis sensor unit. Refer to Removal and Installation.

A/b Warning Lamp Is Off, Pass A/b Indctr Lamp Turns on Intermit. Diagnosis Procedure. Diagnosis Procedure

Diagnosis Procedure

SRS air bag warning lamp is OFF, passenger air bag indicator lamp turns ON intermittently with a person of adult stature seated normally in the passenger seat.

  1. REPLACE OCS SENSORS

      1. Replace the OCS sensors. Refer to Removal and Installation.

      2. Perform zero point reset. Refer to Special Repair Requirement.

    Is symptom still present?

    YES >>

    GO TO 2.

    NO >>

    Inspection End.

  2. REPLACE PASSENGER SEAT CUSHION FRAME

      1. Replace the passenger seat cushion frame. Refer to Disassembly and Assembly.

      2. Perform zero point reset. Refer to Special Repair Requirement.

    >>

    Inspection End.

Seat Belt Indctr Lamp Is On, Pass Air Bag Indctr Is on or Off. Diagnosis Procedure. Diagnosis Procedure

Diagnosis Procedure

Vehicle conditions:

  • Seat belt indicator lamp is ON, passenger air bag indicator lamp is ON or OFF.

  • Passenger seat is unoccupied.

  • Driver seat belt is buckled.

  • Passenger seat belt buckle harness and front seat belt buckle switch RH are OK (buckle passenger seat belt to check if seat belt indicator lamp turns OFF, driver seat belt needs to be buckled).

  1. REPLACE OCS SENSORS

      1. Replace the OCS sensors. Refer to Removal and Installation.

      2. Perform zero point reset. Refer to Special Repair Requirement.

    Is symptom still present?

    YES >>

    GO TO 2.

    NO >>

    Inspection End.

  2. REPLACE PASSENGER SEAT CUSHION FRAME

      1. Replace the passenger seat cushion frame. Refer to Disassembly and Assembly.

      2. Perform zero point reset. Refer to Special Repair Requirement.

    >>

    Inspection End.

    Bcm
    B2c21-23 Front Seat Belt Buckle Switch Lh Dtc Description DTC Description DTC DETECTION LOGIC DTC No. CONSULT screen items (Trouble diagnosis content) DTC Detection Condition B2...

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